Marketing automation is a function that serves two fundamental purposes. Firstly, this eliminates simple repetitive task that consume vasts amounts of a users time. This could be as simple as an auto responded to a website enquiry, through to a long term nurture campaign that ensures customers contact is maintained.
The second element, if set up correct is guiding the contact through the sales process at whatever stage they are at. This helps to nurture the customers or prospect until they are ready to purchase.